1 /* SPDX-License-Identifier: GPL-2.0+ */ 2 /* 3 * Copyright (C) 2018 IBM Corporation 4 */ 5 #include <linux/efi.h> 6 #include <linux/module.h> 7 #include <linux/ima.h> 8 #include <asm/efi.h> 9 10 #ifndef arch_ima_efi_boot_mode 11 #define arch_ima_efi_boot_mode efi_secureboot_mode_unset 12 #endif 13 14 static enum efi_secureboot_mode get_sb_mode(void) 15 { 16 enum efi_secureboot_mode mode; 17 18 if (!efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE)) { 19 pr_info("ima: secureboot mode unknown, no efi\n"); 20 return efi_secureboot_mode_unknown; 21 } 22 23 mode = efi_get_secureboot_mode(efi.get_variable); 24 if (mode == efi_secureboot_mode_disabled) 25 pr_info("ima: secureboot mode disabled\n"); 26 else if (mode == efi_secureboot_mode_unknown) 27 pr_info("ima: secureboot mode unknown\n"); 28 else 29 pr_info("ima: secureboot mode enabled\n"); 30 return mode; 31 } 32 33 bool arch_ima_get_secureboot(void) 34 { 35 static enum efi_secureboot_mode sb_mode; 36 static bool initialized; 37 38 if (!initialized && efi_enabled(EFI_BOOT)) { 39 sb_mode = arch_ima_efi_boot_mode; 40 41 if (sb_mode == efi_secureboot_mode_unset) 42 sb_mode = get_sb_mode(); 43 initialized = true; 44 } 45 46 if (sb_mode == efi_secureboot_mode_enabled) 47 return true; 48 else 49 return false; 50 } 51 52 /* secureboot arch rules */ 53 static const char * const sb_arch_rules[] = { 54 #if !IS_ENABLED(CONFIG_KEXEC_SIG) 55 "appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig", 56 #endif /* CONFIG_KEXEC_SIG */ 57 "measure func=KEXEC_KERNEL_CHECK", 58 #if !IS_ENABLED(CONFIG_MODULE_SIG) 59 "appraise func=MODULE_CHECK appraise_type=imasig", 60 #endif 61 "measure func=MODULE_CHECK", 62 NULL 63 }; 64 65 const char * const *arch_get_ima_policy(void) 66 { 67 if (IS_ENABLED(CONFIG_IMA_ARCH_POLICY) && arch_ima_get_secureboot()) { 68 if (IS_ENABLED(CONFIG_MODULE_SIG)) 69 set_module_sig_enforced(); 70 if (IS_ENABLED(CONFIG_KEXEC_SIG)) 71 set_kexec_sig_enforced(); 72 return sb_arch_rules; 73 } 74 return NULL; 75 } 76